In a bitterly fought dispute over the rights to the gene-editing technology Crispr-Cas9, the U. S. Patent & Trademark Office (PTO) on Wednesday ruled in favor of the Broad Institute in Cambridge, Mass.

The federal regulator's ruling means the Broad Institute, which is a research center affiliated with Harvard and M. I. T., will retain more than a dozen patents granted on the use of the Crispr-Cas9 technology that allows scientists to modify DNA in the cells of humans, animals and plants.

The ruling gave tough blow to the University of California, which is often called the birthplace of the Crispr-Cas9 technique.

UC officials said the ruling left the door open for them to obtain their own patents covering the use of the gene-editing technology for all types of cells.

Prof. Jennifer Doudna, who has been widely credited as an inventor of the gene-editing technique, said, "They have a patent on green tennis balls; we will have a patent on all tennis balls."

New York Law School's associate professor Jacob S. Sherkow, who has followed the dispute closely, called the ruling a "decisive victory" for Harvard and M. I. T. scientists.